The invention relates to vises used during machining processes and, more particularly, to a vise having a fixed central jaw and two movable jaws for holding two work pieces during a precision machining process.
There are several types of vises used during machining, particularly with computer numerically controlled (CNC) equipment. One such device is disclosed in U.S. Pat. No. 4,529,183 to Krason et al. The vise includes two movable jaws and a centrally located fixed jaw for holding two work pieces. However, the mating connection of the jaw member and the slide member is positioned above the work surface of the vise and within the body of the movable jaw, reducing the area of the movable jaw which may be machined during the machining process.
Another vise is disclosed in U.S. Pat. No. 2,564,138 to Walker which includes a mating connection of a jaw and a slide member positioned around a screw shaft. However, the positioning of the mating connection around the screw shaft requires the male connector to have two extensions, weakening the strength of the male connector.
U.S. Pat. No. 5,351,943 to Milz discloses a vise having two fixed jaws and two movable jaws. However, the mating connection includes vertical and horizontal walls, as compared to angularly designed walls which substantially prevent vertical movement during clamping.
U.S. Pat. No. 5,458,321 to Durfee and U.S. Pat. No. 5,002,636 to Swann disclose means for biasing one slide member toward the central jaw. However, Swann uses a block member mounted adjacent to the slide member and Durfee uses an offset assembly attached to the slide, lengthening the overall design of the vise.
U.S. Pat. No. 5,163,662 to Bernstein discloses positioning two vises side-by-side. However, the edges of the vises do not interlock together, creating the possibility of movement of one vise with respect to the other.
U.S. Pat. No. 4,529,183 to Krason discloses the slide member having a collar portion. However, the collar portion does not cover the entire length of the screw shaft, exposing the threads of the screw shaft to machining chips and other debris.
Therefore, what is needed is an apparatus for holding work pieces which utilizes a low profile type of mating connection, a soft base and hard guide rails, a compact means for controlling sequential movement of the movable jaws, means for interlocking the bases of the vises, and means for protecting the screw shaft.